1. Field of the Invention
The present invention relates to the spreading of fill or paving material in a desired region and particularly to the controlled application, in a travel lane or a verge area of a highway right-of-way, of a finishing material. More specifically, this invention is directed to road construction apparatus and especially to a "paving" machine which may selectively be employed for application of material to a travel lane or delivery and distribution of material to a trench or shoulder region which is laterally offset from a travel lane. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
Road construction methods and apparatus are well known in the art. The equipment employed in highway construction includes devices which may be generally described as paving machines. A typical prior art paving machine will have a chassis which supports a skip at its front end. The skip, to which the material to be applied over the road bed is supplied, is conventionally provided with pivotal side-wall sections which define a filling funnel therefor. Such a paving machine also supports, at the rear of the chassis for working the applied materials, a device known in the trade as a "beam". The skip will have a discharge opening at the bottom and a conveyor moves material which is dumped into the skip, and subsequently flows out the bottom thereof, from the front to the rear of the paving machine. This material will be distributed over the length of the beam by a "distributing worm". The beam of prior art paving machines is typically comprised of a primary beam and a pair of oppositely disposed, adjustable beam extensions so that the material being deposited on the road bed can be spread across the appropriate area. The distance the opposed beam extensions project from the main beam will usually be separately controllable via hydraulic actuators to selectively control the lane width. The beam may also have stamping and/or vibration units which ensure proper distribution of the material supplied via the distributing worm.
The prior art paving machines are usually tracked vehicles. During road construction or repair, trenches are often excavated alongside the outermost travel lanes. During finishing of the road, it may be necessary to close such trenches and/or to form a shoulder area or breakdown lane. In order to employ a prior art paving machine to fill a trench or lay down material for a shoulder region, the tracked vehicle previously had to be positioned so as to straddle the trench or shoulder region. In many cases either the terrain is unsuitable for operating the paving machine with the trench or shoulder region located between the tracks or there is insufficient space available for operation of the paving machine with a trench or shoulder region straddled thereby.